Fungal volatile organic compounds: emphasis on their plant growth-promoting

Fungal volatile organic compounds (VOCs) commonly formed bioactive interface between plants and countless of microorganisms on the above- and below-ground plant-fungus interactions. Fungal-plant interactions symbolize intriguingly biochemical complex and challenging scenarios that are discovered by metabolomic approaches. Remarkably secondary metabolites (SMs) played a significant role in the virulence and existence with plant-fungal pathogen interaction; only 25% of the fungal gene clusters have been functionally identified, even though these numbers are too low as compared with plant secondary metabolites. The current insights on fungal VOCs are conducted under lab environments and to apply small numbers of microbes; its molecules have significant effects on growth, development, and defense system of plants. Many fungal VOCs supported dynamic processes, leading to countless interactions between plants, antagonists, and mutualistic symbionts. The fundamental role of fungal VOCs at field level is required for better understanding, so more studies will offer further constructive scientific evidences that can show the cost-effectiveness of ecofriendly and ecologically produced fungal VOCs for crop welfare

Multiple Translocation of the AVR-Pita Effector Gene among Chromosomes of the Rice Blast Fungus Magnaporthe oryzae and Related Species

Magnaporthe oryzae is the causal agent of rice blast disease, a devastating problem worldwide. This fungus has caused breakdown of resistance conferred by newly developed commercial cultivars. To address how the rice blast fungus adapts itself to new resistance genes so quickly, we examined chromosomal locations of AVR-Pita, a subtelomeric gene family corresponding to the Pita resistance gene, in various isolates of M. oryzae (including wheat and millet pathogens) and its related species. We found that AVR-Pita (AVR-Pita1 and AVR-Pita2) is highly variable in its genome location, occurring in chromosomes 1, 3, 4, 5, 6, 7, and supernumerary chromosomes, particularly in rice-infecting isolates. When expressed in M. oryzae, most of the AVR-Pita homologs could elicit Pita-mediated resistance, even those from non-rice isolates. AVR-Pita was flanked by a retrotransposon, which presumably contributed to its multiple translocation across the genome. On the other hand, family member AVR-Pita3, which lacks avirulence activity, was stably located on chromosome 7 in a vast majority of isolates. These results suggest that the diversification in genome location of AVR-Pita in the rice isolates is a consequence of recognition by Pita in rice. We propose a model that the multiple translocation of AVR-Pita may be associated with its frequent loss and recovery mediated by its transfer among individuals in asexual populations. This model implies that the high mobility of AVR-Pita is a key mechanism accounting for the rapid adaptation toward Pita. Dynamic adaptation of some fungal plant pathogens may be achieved by deletion and recovery of avirulence genes using a population as a unit of adaptation

Genome Sequencing and Comparative Transcriptomics of the Model Entomopathogenic Fungi Metarhizium anisopliae and M. acridum

Metarhizium spp. are being used as environmentally friendly alternatives to chemical insecticides, as model systems for studying insect-fungus interactions, and as a resource of genes for biotechnology. We present a comparative analysis of the genome sequences of the broad-spectrum insect pathogen Metarhizium anisopliae and the acridid-specific M. acridum. Whole-genome analyses indicate that the genome structures of these two species are highly syntenic and suggest that the genus Metarhizium evolved from plant endophytes or pathogens. Both M. anisopliae and M. acridum have a strikingly larger proportion of genes encoding secreted proteins than other fungi, while ∼30% of these have no functionally characterized homologs, suggesting hitherto unsuspected interactions between fungal pathogens and insects. The analysis of transposase genes provided evidence of repeat-induced point mutations occurring in M. acridum but not in M. anisopliae. With the help of pathogen-host interaction gene database, ∼16% of Metarhizium genes were identified that are similar to experimentally verified genes involved in pathogenicity in other fungi, particularly plant pathogens. However, relative to M. acridum, M. anisopliae has evolved with many expanded gene families of proteases, chitinases, cytochrome P450s, polyketide synthases, and nonribosomal peptide synthetases for cuticle-degradation, detoxification, and toxin biosynthesis that may facilitate its ability to adapt to heterogenous environments. Transcriptional analysis of both fungi during early infection processes provided further insights into the genes and pathways involved in infectivity and specificity. Of particular note, M. acridum transcribed distinct G-protein coupled receptors on cuticles from locusts (the natural hosts) and cockroaches, whereas M. anisopliae transcribed the same receptor on both hosts. This study will facilitate the identification of virulence genes and the development of improved biocontrol strains with customized properties

Die Behandlung flüchtiger Radionuklide in Wiederaufarbeitungsanlagen für Kernbrennstoffe

Die wichtigsten flüchtigen Radionuklide werden genannt, ebenso der Ort der Freisetzung und die Freisetzungsraten für Edelgas, Jod und Tritium in einer Wiederaufarbeitungsanlage. Aufgaben und Methoden der Reinigung kontaminierter Abgase werden beschrieben, wobei einzelne Verfahren in Fließbildern dargestellt sind. In einem kurzen Überblick wird die Endlagerung flüchtiger Radionuklide erläutert

Theoretische Untersuchungen zur Kritikalität von Wirbelschichtöfen fürHTR-Brennelemente

Die geometrischen Abmessungen eines Wirbelschichtreaktors zur Graphitverbrennung im HEAD-END der Wiederaufarbeitung der Brennelemente gasgekühlter Hochtemperaturreaktoren werden maßgeblich von dessen kritisch sicherer Auslegung beeinflußt. Anhand geplanter gas- und wassergekühlter Wirbelschichtreaktoren mit einer Wiederaufarbeitungskapazität von 8500 und 17000 MWe wird der Einfluß der Moderatoren Graphit und Wasser untersucht. Es werden Modelle zur Abschätzung der Auswirkungen störfallbedingter Unterbrechungen der Gasanströmung sowie eines Kühlwassereinbruchs in das Verbrennungsgut entwickelt. Es zeigte sich, daß beiRealisierung technisch interessanter Graphitumsätze ein kritisch sicherer Betrieb nur in einem gasgekühlten Wirbelschichtreaktor möglich ist, während ein Wassereinbruch bei einem wassergekühlten Wirbelschichtreaktor auch bei Anwendung heterogener Absorber zu einem überkritischen System führen kann. Die vorliegende Arbeit entstand im Rahmen einer Zusammenarbeit des Lehrstuhls für Reaktortechnik der RWTH Aachen mit dem Institut für Chemische Technologie der KFA Jülich

Kosten des Verbrennungs-HEAD END's einschließlich der Kr-Abtrennungbei der Wiederaufarbeitung von HTR-Brennelementen

Es werden die C-Verbrennung und die Kr-Abtrennung während des Verbrennungs-HEAD ENDs der Wiederaufarbeitung von HTR-Brennelementen beschrieben. Die Kosten für Bau und Betrieb eines Verbrennungs-HEAD ENDs der Wiederaufarbeitungskapazitäten von 5000 bis 50000 MWe-HTR-Leistung wurden ermittelt. Die Kostenschätzungen gliedern sich in Investitions- und Betriebskosten, ferner nach dem Anteil des N$_{2}$-Gehalts im Verbrennungsabgas, der stark kostenbeeinflussend wirkt. Es zeigt sich, daß für den Fall der Kr-Abtrennung aus dem Verbrennungsabgas sowohl die Investitionskosten als auch die Betriebskosten des HEAD ENDs für N$_{2}$-haltiges Abgas wesentlich über denjenigen des N$_{2}$losen liegen. Die C-Verbrennung des Graphits der HTR-Brennelemente sollte deswegen nur mit N$_{2}$-freiem Anströmgas durchgeführt werden